We Get Lean With A Little Help From Our Friends

For decades we've been told that our creeping overweight and lack of physical activity is our fault -- that we lack self-discipline, that we're lazy, that we're self-indulgent. With such an accusatory finger pointed at us, it's no wonder we despair. But is our overweight and unhealthy lifestyle really our own fault? Do we simply lack willpower? Are we just lazy overeaters?

As a researcher in this field, my answer is, "I don't think so." I believe that our physical and social environment is the key to a healthy body weight. In my 10th and newest book, The Social Network Diet: Change Yourself, Change the World, I outline this concept.

Take Martha. At the age of 51, Martha's weight had ballooned to a high of 210 pounds. She was living in Atlanta at the time, a city with serious obstacles to healthy living -- among them, roads made for driving, not walking, and a tradition of heavy southern cooking. Many of Martha's Atlanta friends were also overweight. "I had pretty much given up on exercising," she told me. Then, in 2009, Martha moved to Denver. There she found an environment more conducive to physical activity and good nutrition, as well as a network of friends with an active, healthy lifestyle. A little over a year later, she had lost 53 pounds, was walking regularly with her new friends, joining a neighbor for spinning classes at the local recreation center, and eating better than she ever had.

As Martha's story suggests, our food intake and physical activity are not matters of simple willpower. New research backs this up. Study after study suggests that the crisis we're facing as individuals and as a nation is only minimally caused by our own poor choices -- it is primarily a reflection of our surroundings, both our social and our physical environments.

In other words, it's not you; it's the company you keep and your surroundings.

Only recently have we become aware of just how tight the relationship is between people and their environment. This concept, known as the socioecological model, recognizes that our behavior is shaped to a large extent by forces outside of our control, in our social and physical surroundings. A slew of factors beyond willpower affect our health and health-related behavior, from our genes, to our family dynamics, social ties, and the place we live.

Habits are hard to change. But when your environment changes, so do your habits. The point is this: To make healthy living easier, we need to create an environment that supports our health rather than sabotaging it. Fortunately, we now have the tools to do so -- key among them, social networks.

When we hear the term "social network" these days, we tend to think of online networks. But social networks are as old as humankind itself. They are defined simply as groups of people and the connections between them. Social networks are complex, powerful entities that shape our thoughts and habits and can function either to our detriment or to our advantage. For years, we've known that social networks influence who smokes, who drinks, who contracts sexually transmitted diseases, and even people's happiness. Now we understand that they can also have a profound influence -- either positive or negative -- on our body weight and physical activity levels.

A study that was just published in the journal Obesity provides further evidence of the power of social networks for losing weight. Colleagues at Miriam Hospital at Brown University analyzed the results from the "Shape Up Rhode Island" public health campaign. The campaign consisted of an intensive 12-week statewide weight loss competition. Through aggressive outreach, overweight and obese individuals were invited to join a team. In the end there were 3,330 individuals assigned to 987 teams that consisted of five to 11 members. They were all given support to eat more healthfully, exercise more, and monitor their progress. The teams were encouraged to compete against each other. The results of the study were fascinating. Teammates significantly influenced each other's weight loss. On average, teammates achieved similar weight loss within teams. And participants who said that their fellow teammates played a significant role in their success lost the most amount of weight. Those individuals who reported a strong social influence lost the most weight. In short, the teams that developed strong social networks lost the most amount of weight as a team and as individuals.

Miriam E. Nelson, Ph.D., is a leading nutrition, physical activity, and health researcher and New York Times best selling author. Her latest book, written with Jennifer Ackerman, is The Social Network Diet: Change Yourself, Change the World (FastPencil 2012). Visit Dr. Nelson on www.StrongWomen.com